PROCESS AND DEVICE FOR FILTERING AND HUMIDIFYING AIR FLOW

Abstract: The invention concerns a process and a device for filtering and humidifying air flow, with particles in suspension, characterized by the simultaneous execution, in the same device, of the function of the retention of the particles, its collection and transport and of the humidification of the air flow. The function of retention of the particles is executed through the circulation of the flow (6, 5, 20, 21), by a reticulated structure (3, 13, 14) in such a way to produce at least a sharp change (9, 15) in its direction of circulation, thus resulting in the collision of the particles on the walls of the structure. That function is complemented through the humidification of the structure and from the action of water jets (10) emitted by a dispersive-projector (4, 14) and directed toward the surface of the structure which is provided with rotation (7, 23), this action executing, at the same time, the collection and transport of the particles to the exterior (8, 22). The function of humidification is a result of the high water dispersion on the surfaces of the air flow circulation (9, 15, 16, 17, 19), which results in the greater contact between the air flow and the water. Devices according to the invention can execute with great efficiency the retention and collection of dust and other industrial residuals that are emitted to the atmosphere and can be used for other uses, such as, in air conditioning circuits.

Description: DESCRIPTION PROCESS AND DEVICE FOR FILTERING AND HUMIDIFYING AIR FLOW Technical domain The invention regards a process and a device for filtering and humidifying an air flow, including the simultaneous performance, in the same device, of the function of retention of the particles in suspension in the flow, of the function of the gathering and transportating of those particles to the exterior and the function of humidifying the air of the flow. Previous technique In the processes and.devices already known, these functions are performed separately, distinguished by devices of their own, the gathering and transportation of the particles dealt by a periodical maintenance. In filtering devices for air with suspended particles, the process for the retention of the particles, consisted until now, of the interposition on the flow of a barrier of filtering material, which is made up of a reticulation of appropriate fibres, arranged in a way to build porous of smaller degree than the dimension of the particles whose retention is intended. However, the efficiency of this process is not sufficient,as the smaller particles are not retained, those whose dimension is inferior to the degree of porousness settled in the material. The efficiency degrades due to the accumulation of particles which fill the area of the reticles, making the flow of the air more and more difficult, diminishing its debt which will become virtually null, if the replacement of the filtering material does not take place, before. In the air humidifying devices, a process has been used which consists in submitting the water to a high frequency movement, obtained by electromagnetic action. Explanation of the invention According to our invention, all the problems which we SUBSTITUTE SHEET mentioned above, related to filtering devices, are avoided with the substitution of the static process of interposition of a porous material by a dynamic process, which consists in the fact that it includes the simultaneous performance of the function of retention of the particles in suspension in the flow, of the function of their gathering and transportation and of the function of humidifying the air of the flow, by the action of the movement of the flow itself and the action of water jets and the use of structures with a rotating movement. The function of retention of the particles is fulfilled, organizing a reticulated structure disposing of a rotating movement and constituted by a set of narrow paths, whose walls exhibit rugosities, collecting and distributing the circulation of the air flow; each one of these paths is shaped in a way that produces at least one sudden change in the direction of the flow circulation, with a very marked angle in a small radius, resulting from these dispositions the collision of the particles against the walls of the circulation paths, and from this, being the value of the inertia of the particles greater than the inertia of the air, the particles will not be able to change its direction according the same angle and the same radius. This effect is complemented by the humidification of the paths for the circulation of the flow, which produces an attractive action over the particles that corresponds to the surface tension of the water. The movement resulting from the emission of water jets directed against the reticulated structure, with a dispersive effect in the circulation paths of the flow, also contributes to the function of retention of the particles and performs the function of gathering and transportation of those particles. The function of humidifying the air of the flow results from the strong scattering of the water on the surfaces of the flow circulation which helps a closer contact between the water and the circulating air. The applicability of the referred effects and actions, is explained and established next, with the help of the detailed description of two illustrative examples which have not a limitative character, of the conception of devices that SUBSTITUTE SHEET perform in a better suited manner the present invention. These examples are illustrated by the attached drawings: Figure 1, depicts example 1, of a device according to the invention, through a cut longitudinal to the rotation axis, representing a preferred shaping of the reticulated structure (3) a shaping of the dispersive water projector (4), which also illustrate the positioning of the means (7) that provide the rotation of the reticulated structure and of the casing surrounding these components, which is provided with openings (6), an outlet (7) to allow the circulation of the flow " and an outlet (8) for the removal of the particles. The figure display the lines and direction of the circulation of the air flow (9) and lines and direction of the projected water (10). Figure 2, also depicts example 1, through a cut transversal to the rotation axis, representing a preferred shaping of the reticulated structure (11, 12), the centered position of the dispersive-projector of the water (4) and the indication of the opposite directions that are followed by the circulation of the air flow (9) and by the circulation and dispersion of water (10) when it crosses the reticulated in the structure. Figure 3, depicts the example 2, of a device according to the invention, through a cut longitudinal to the rotation axis, representing a preferred shaping of the reticulated structure (13, 14), a shaping of the dispersive water projector (18), preferred shaping of cylinders with perforated slits (16), a casing that surround these components provided with inlet (20), outlet (21) for the air flow and outlet for the removal of the particles (22). The figure also display the direction and reversal of the circulation of the air flow (15) and the positioning of means (23) providing the rotation of the reticulated structure. Figure 4, also depicts example 2, through a cut transversal to the rotation axis, representing a preferred shaping of the reticulated structure (14), a preferred positioning of the dispersive-projector (18), the preferred shaping of cylinders with perforated slits (17) and the direction and reversal of the circulation of the air flow in the incised cylinders (19). In agreement with the invention and according to example 1, the reticulated structure (3) is made by a due extent of a SUBSTITUTE SHEET enduring material, with laminated thickness and with a reticulated texture, preferably an extent of metallic net, in which the area of each reticulum is in accordance with the average dimension of the particles in suspension in the air flow. A preferred shaping of the structure is the one that result from a certain number of folds, made up in alternated directions in a extent of the net, followed by the bending of the net, in a way that the vertices of the folds, inner (12) and outer (11) become equidistant from each other and have a common rotation axis. The resulting structure from above, is provided with lids at both sides, one of them being provided with one opening which follows the position of the inner vertices, as to allow the air flow. In agreement with the invention and according to the example 1, the dispersive water projector (4) is positioned coincident with the rotation axis of the reticulated structure and is made up of an elongated structure, preferably a tube with several series of thin peripheral slits distributed in a regular manner along its length. These slits, fed by water at adequate pressure give raise to water jets with laminated shape, directed against the inner surface of the reticulated structure (10). In agreement with the invention and according to the example 1, the function of each component is explained as follow: The air flow, with particles in suspension, is admitted at the inlets (6) of the casing of the device, then it is distributed as to surround the outer area of the reticulated structure, circulates with appropriate speed between the faces of their folds (9) , takes an average direction which makes a pronounced angle with the face of the reticles, in a way that in order to cross these reticles and enter the inner collector it has to change direction abruptly over that pronounced angle within a radius extremely short. The air has less mass than the particles and so less inertia, which allows it to change direction easier. The particles with higher mass and because of that with higher value of inertia, can not change direction within the same SUBSTITUTE SHEET angle and radius, and so they collide against the wet walls of the reticles, where they keep bounded by the attraction of water due to the water surface tension. This action is assisted by the centrifuge effect that is associated to the particles by the rotational movement of the reticulated structure; this effect has an action into the opposite direction of the particles circulation. The dispersive action of water resulting from the .impact of the water jets against the reticulated structure which has an opposite direction (10) relative to the flow circulation (9) also assists the action of retention of the particles and, at the same time, take over its gathering and removal out of the device (8). In agreement with the invention and according to the example 2, a preferred shaping of the reticulated structure results of the grouping of a number of elements, each one of them with the shape of a continuous and circular band, having in each face several series of recesses (13) and several series of salience (14) all mutually concentric and concentric with the band, inscribed in a alternative manner such us a hollow in a face correspond to a saliency in the opposite face. The grouping of the bands is carried out in a way that each hollow in the face of an element corresponds to a saliency in the face of the neighbouring element, and considering an adequate mutual spacing in order to keep, between two neighbour elements, an inter-space (15). Each one of these spaces, being narrow and with repeated changes in the direction of the circulation, perform as a number of reticles, in which the effect of inertia is felt intensely since the angles corresponding to the change in direction of the air flow are very pronounced. One important advantage of this kind of shaping of a reticulated structure is due to the possibility of including a larger reticulated area inside the same space, and so to obtain smaller devices for a given filtering capacity. The preferred shaping of cylinders with slits are those depicted by the figures (3, 4) displaying the fact that the relative position of the slits alternates from cylinder to cylinder, for the longitudinal position (16) and for the SUBSTITUTESHEET radial position (17). The dispersive water projector, has the same features as the one which is described in example 1, being distinct, only, in its position regarding the reticulated structure since it is placed in its exterior (18) , parallel to the rotation axis, not coincident with it. In agreement with the invention and according example 2, the functions of their components are depicted in what follows: The air flow, with particles in suspension, is admitted at the inlet (20) on the case of the device, distributes itself as to surround the reticulated structure and circulates along each of the inter- spaces (15). The particles in suspension in the flow, due to their larger value of inertia can not describe the successive and narrow turning angles during its circulation along each of the inter¬ spaces, colliding against their walls which, being constantly wet, operate the retention of the particles. The dispersion of the water from the jets, performs, as in the example 1, the function of humidifying the intervallic spaces and that of the incised surfaces of the cylinders. The function of the cylinders with slits, is to retain the drops of water, originated from the remainder of the jets, which go beyond the reticulated structure and support an extension of the surfaces through which water evaporates. Due to the drawing of the slits and to the alternate relative position from cylinder to cylinder, the drops of water, due to its inertia, are not able to describe the strongly curved path imposed by the sudden change in the direction of their circulation (19), breaking up on the surface of the first cylinder, to form a thin film of water. One fraction of this is evaporated, another fraction reaches the edges of the slits, is taken by the flow and breaks on the surface of the next cylinder; the remaining water is collected in the down part of the cylinder and due to its weight returns to the reticulate and join the water that retained and transport the particles (22). The drops taken by the flow to the second cylinder, as they are originated from a much thinner film of water, have now a very small diameter, but their inertia is still enough to SUBSTITUTE SHEET distribute over its surface setting up, there, a new area for evaporation. This operative way repeats regarding the third cylinder and could repeat successively, depending only upon the level of humidness required for a certain volume of air. As it can be deduce from the description of these examples of devices, the one of example 1 will preferably be used for the retention of particles of greater size and for a low level of humideness required. The one of example 2 will preferably be used for the retention of thinner particles and for a higher level of humidness required. Devices according example 1, can be used with very good efficiency in the retention and gathering of dust and other industrial residues, thrown to the atmosphere through the chimneys of a great deal of industrial plants. For this reason from the use of these devices it will result an remarkable diminution of the atmospheric pollution. Devices according example 2, can be used, with remarkable advantage, on conditioned air circuits and on industrial situations requiring dust free and humidified air. SUBSTITUTESHEET

Claims: AMENDED CLAIMS [received by the International Bureau on 23 January 1995 (23.01.95); original claims 1-10,12 and 13 amended ; other claims unchanged (3 pages)] 1. Process for the filtering and humidification of an air flow, containing particles in suspension, which executes simultaneously, 5 in one single device, the retention, the gathering and the removal of the particles and the humidifying of the air of the flow, which comprehends the organization of structures built of flat extensions of reticulated surfaces where the air flow circulates, associated to the attractive effect over the particles, which 10 results from the surface tension of water blades distributed on the surfaces, characterized by the fact that the ways in which the structures are organized and the ways of formation of the reticules of the surfaces, have a specific construction with the purpose of obtaining, at least,one sudden change in the direction of the 15 linear motion of the flow, in order to induce in those particles a substantial increase of the inertia effect, from which does result its collision with the surfaces, which, associated to the attractive action of the water blades that are in those surfaces distributed, leads to the retention of the particles. 20 2. Process according to claim 1, characterized by the fact that the function of retention of the particles is executed by organizing structures with a specific modelling (3,13,14), composed by the conjunction of flat planes, in such a way so as to shape 25 narrow paths, whose walls present rugosities, those paths receiving and distributing the circulation of the air flow, each of these paths being modelled in such a way so as to obtain, at least, a sudden change (9, 15) in the direction of the air flow circulation, following a very marked angle in a small radius, resulting from 30 these dispositions a substantial increase of the effect of the inertia of those particles and the consequent collision of the particles against the walls of the circulation paths of the air flow. 353. Process according to claims 1 and 2, in which the function of retention of the particles is complemented by the humidification of the walls of the reticulated structure, this one having a slow rotating movement, characterized by the fact that the formation of continuous blades of water is privileged, these blades being 40 equally distributed by the walls of the circulation paths of the air flow in order to improve the consequences of the attractive effect of the water surface tension. . Process according to claims 1, 2 and 3, in which the movement resulting from the emission of water jets directed to tne reticulated structure with a dispersive effect over the circulation paths of the flow (9, 15) contributes to the function of retention of the particles characterized by the fact that the dispersive effect is greatly increased by the laminated shape of the water jets. 5. Process according to claims 1 to 4, in which the humidification function of the air of the flow results from the dispersion of the water in the circulation paths of the flow, characterized by the fact that lamination of water jets decreases the effect of its spraying and the resulting dragging of water by the flow itself. 6. Device for the filtering and humidification of air flow, according to the previous claims including (example 1) of a reticulated structure (3), a dispersive - projector (4), emitting water jets (10) directed towards the paths of the flow and a case enveloping these components, with adequate inlets (6) , outlet (5) for the exit of the air flow and outlet (8) for the removal of the particles and of the excess water, characterized by the fact that the reticulated structure is build up of a specific grouping of blade like elements with a plane shape and by the fact that the structure is associated to a dispersive - projector which emits water jets of a laminate shape. 7. Device according to claim 6, characterized by the fact that which one of the laminated elements is made up of a plane extension of an enduring material of blade like thickness and with a thin reticulated texture, for instances, a thin metal grid. 8. Device according to claim 6, characterized by the fact that the moddeling of the reticulated structure is the result from a number of folds, made up in alternated directions on a plane extension of laminate material with reticulated texture,in such a way that allows to obtain plane elements (3, fig. 2) linked with each other in a consecutive manner these elements being positioned in a longitudinal and symmetrical way around a rotating axis in a way that the vertices of the folds, both those of the outer group (11) and those of the inner group (12), are equidistant in each group. 9. Device according to claim 6, characterized by the fact that the water dispersive projector is made up of an elongated structure (4) which presents several series of narrow peripheral slits distributed in a regular manner according to its length, in such a way that the water jets emitted have a laminate snape, and by tne fact that it is associated to the reticulated structure so as to occupy, preferably, a inner position in relation to the structure, coincident with its axis of rotation. 5 10. Device for filtering and humidification of a air flow according to the previous claims, characterized by the fact that it includes in an essential manner (example 2) a specific modellation of a reticulated structure (13,14) having this one a slow rotating 10 movement and being associated to a circular set made up of elongated blades (17) and to a dispersive water projector (18). 11. Device according to claim 10, characterized by the fact that the reticulated structure is a grouping of a number of elements 15 each having the form of a continuous and circular band, having in each side series of recesses (13) and series of salients (14), concentric with the band, inscribed in an alternative manner such that a recess in a face corresponds to a salient in the opposite face, the grouping of the bands is carried out in a way that each 20 hollow in the face of an element corresponds to a saliency in the face of the neighbouring element, and considering a distancing in order to obtain, between two neighbour elements a intercalated area(15), appropriate to the reticulation desired. 2512. Device according to claims 10 and 11, characterized by the fact that each blade is modelated longitudinally as defining two parts, united with each other, and each one at different distance of the inner limit of the structure, in such a way that the blade part closer to that limit overlaps the far away part of the next blade 30 (17) being the two parts separated by a narrow distance on which circulates the air flow and being the orientation of that overlapping such that the set of blades oppose to the entry of water from the dispersive projector to its interior. 35 13. Device according to claims 9 to 12, characterized by the fact that the dispersive projector of water is associated to the reticulated structure so as to occupy, preferably, an external position in relation with the structure and parallel to its axis of rotation, which does result in an important increase of the general 40 performance of the device. STATEMENT UNDER ARTICLE 19 Claim 1 - It has been amended in order to limit, partially, its claiming breadth so as to claim only the characteristics of the process which specify the referred examples. Claim 2 - It has been amended in order to improve the comprehension of its text and underline the importance of a rather important exploitation of the inertia of the particles related to the quality of the process. Claim 3 - It has been amended in order to limit, partially, its claiming breadth and underline the importance of the building of water blades which improves the exploitation of the surface tension of water. Claim 4 - It has been amended in order to limit, partially, its claiming breadth and underline the importance of the building of water blades which improves the dispersive effect of the water jets. Claim 5 - It has been amended in order to limit, partially, its claiming breadth and underline the importance of the building of water blades so as to diminish the spraying and dragging of water by the air flow. Claim 6 - It has been amended in order to limit, partially, its claiming breadth and so as to claim only the specific and essential characteristics of the referred example. Claim 7 - It has been amended so as to characterize in a more clear way the specific elements which are referred. Claim 8 - It has been amended so as to characterize in a more clear way the shaping of the structure. Claim 9 - It has been amended in order to make clear that the function of the narrow slits included in the dispersive - projector is to obtain a lamination of the water jets. Claim 1 0 - It has been amended in order to limit, partially, its claiming breadth and so as to claim only the specific and essential characteristics of the referred example. Claim 1 2 - It has been amended in order to limit, partially, its claiming breadth and to characterize in a more detailed way the set of lamellae and underline its function made explicit in figure 4. Claim 1 3 - It has been amended in order to extend its claiming breadth and to underline the importance of the specific shape of the dispersive - projector so as to increase greatly the performance of the general operative function of the devices.

Inventors: BAPTISTA FERNANDO AUGUSTO, PEREIRA DIAS BAPTISTA JOAO MAN, BAPTISTA, FERNANDO, AUGUSTO, PEREIRA DIAS BAPTISTA, JOAO, MANUEL
Applicants: BAPTISTA FERNANDO AUGUSTO, PEREIRA DIAS BAPTISTA JOAO MAN, BAPTISTA, FERNANDO, AUGUSTO, PEREIRA DIAS BAPTISTA, JOAO, MANUEL
Application year: 1994
Main classification: B01D50
IPC codes: B01D45, B01D50